From [DailyKos] and [MORE] and [MORE] A fallacious, scurrilous "crosscheck" list of voters' names across states, dubbed "Interstate Crosscheck", flagged "suspected double voters" across state lines, by sending participating states the names of voters that were only partial matches. Screen shot of some of the matches is shown directly below. A much larger, clearer image of the name matches can be seen here at the reporter's website (gregpalast.com). Note Greg Palast uncovered Crosscheck in a research project published by Al Jazeera America, which is no longer operating. The reporting is republished here [November 2014], and at his own website. It's clear to see, especially in the larger image, that these "Case #s" of 2 names are generally not of the same person. These are persons with common last and first names.
More than 2 dozen states participate in the "Interstate Crosscheck" program, run by Kansas Secretary of State Kris Kobach -- including Pennsylvania, Michigan, North Carolina and Ohio.
Although the program claims to possess information on voters by entire full name, SSN and birth year and date, it is obvious just scanning the partial case lists that reporter Greg Palast reviewed, that all the matching info is not used.
A partial match will allege fraudulent potential double voters of distinct people. The list is obviously so flawed that Florida eventually opted out of Interstate Crosscheck. Oregon stopped participating as well because the "data we received was unreliable", according to the SoS office.
Of course, not every person on the list sent to state and county elections offices gets purged from registration lists. It depends how well the state researches the list, and pares it down.
However, the problem with sloppy, partial match lists alleging fraudulent voter registration is it catches up innocent people, and not randomly. Statistically, the most common names are not distributed randomly across ethnic groups.
The three states' lists analyzed by Al Jazeera America are heavily weighted with names such as Jackson, Garcia, Patel and Kim -- names common among African-Americans, Hispanics and Asian-Americans, groups who typically vote Democratic.
1 in 7 African-Americans in those 27 states are listed as under suspicion of having voted twice, 1 in 8 Asian-Americans and 1 in 8 Hispanic voters. For white voters, the number is 1 in 11.
Consider 2014, one state: "In North Carolina, where Republican Thom Tillis won over incumbent Sen. Kay Hagan by just 48,511 votes, the voter purging system known as Crosscheck tagged an alarming 589,393 North Carolinians as possible illegal double voters (though state elections officials cut that down to roughly 190,000), according to Al Jazeera America."
Realize that once someone is on a suspect purge list maintained by the SoS or county elections board, when they show up to vote, they may be forced to vote by Provisional Ballot.
Provisional ballots are not counted on Election Day, and are not resolved until further investigation satisfies elections officials.
I haven't found it easy to find the count of provisional ballots in states like PA and Michigan, to see how many would be voters were diverted, and how many such ballots were eventually discarded or counted.